This invention relates to ballasts for HID lamps and particularly those ballasts designed to provide instant restrike capability to an HID lighting installation. An HID lamp utilizing a ballast without instant restrike capability requires a delay of 5 to 15 minues in order to restrike when it is hot. Such a delay is an obvious safety problem and an inconvenience for both outdoor and indoor lighting applications.
In U.S. Pat. No. 3,732,460 dated May 8, 1973 issued to Wattenback is disclosed a circuit for instant restart of a high pressure discharge lamp. The circuit uses a current limiting inductor, a power factor correcting capacitor, and an igniter for kilovolt, radio-frequency pulses. The circuit as shown is quite expensive.